Process and device for producing flat wood shavings



Feb. 24, 1959 1.. PALLMANN 2 Sheets-Sheet 1 Filed Oct. 14, 1953 mvsmmLuowe PA m BY:

Feb. 24, 1959 j L. PALLMANN PROCESS AND DEVICE FOR PRODUCING FLAT WOODSHAVINGS v 2 Sheets-Sheet 2 Filed Oct. 14, '1953 I llllllllllll e2,874,909 rRocEss AND-DEVICE FORPRODUCING FLAT wool) SHAVINGS Liidwiglallmann, Z w eibrucken, Pfalz, Germany Ap plication iocaiber 14, 1953,Serial No. 386,079

Claims. C1.z41-'-2s ing medium are required, and the resulting high costdoes not fit in with the fact that thesesheets, in particular withreference totheir resistance to tearing and bending, do not nearlyattain the strength values of natural wood.

To improve the mechanical quality of the 1 hard board sheets producedfrom wood waste, a method has been adopted in recent times-of making thesheets exclusively oratleast'to a preponderating extent of thin flatshavings preferably of several centimetres in length, wherebyapartfromthe considerable increase in strength-a considerable saving inbinding medium is also obtained and therewith a considerable decrease incost. [*Ijnthe pastthe'long "fiat shavings required for the fpioductionof these'hard boardshee'ts weremade substantially ofhigh-grade "wood,which is similarly used for the production of wood'woolrthe wood to beshaved, in the'forrn of longerpiecea'being clamped in a holding andclampingarrangement and moved against a set of ""plani'ngk'nivesymounted on'acy1ir'idrical surface ofa.

rotating drum.

t In the process according to the prior art, the wood piece after beingshaved to'a certain extent, had't'o be rejclamped in the holding andclamping device and before this reclarnp ing, the'hol'ding andreclamping" device had tobefbroughfback' to its ting position. Thisrequired a rather slow and cumbersome operation. Furthermore, thenecessity of clampinga portion of the wood piece1-in the clampingdevicemade, a complete shaving of the wood piece impossib1e., u l

In the process according to the invention the wood Waste to be shaved isbrought into a rotating drum, provided on the inside of its preferablycylindrical shell with planing knives. Within the drum there rotatesopposite to the direction of rotation of the drum a holding or beatingcross by which the wood waste brought into the drum, Whose length in thedirection of the fibre is shorter than the length of the planing knivesand correspondingly shorter than the width of the inner space of theknife drum, is held or moved against the knife drum.

The pressing of the wood pieces to be shaved against the planing kniveson the inner surface of the drum is brought about on the one hand by thecentrifugal forces acting on these pieces of wood, which with decreasingsize and decreasing weight of these waste wood pieces are assisted bythe air current directed centrifugally out of the drum to the outside,and, on the other hand by the flied PM radial component of the of-theknife drum. erably-flatcircular disc 8, "on which the pressing ring 10 p2,874,909 Patented Feb. 24, '1959 ,2 I tangential acceleration given tothe wood waste by'the oppositely rotating beater arms of the beatercross.

The process and arrangement according to the invention differs favorablyfrom the above-mentioned known procedures and machines intha't no wasteis left and that waste pieces of only a few centimetres length can becompletely shavedup. In addition there is the very important advantagethat with the process according to the present invention the work can bedone in a continuous manner. It-is on1y-necessary to fill into thefilling hopper of the machine the waste which has been brought to theright length and the work can proceed without any interruption by theunprofitable drawing'back "of -a h0lding or clamping device, or by theunclamping, pushing forward and reclamping of the wood to be shaved.

than across the direction of the fibres-the wood waste brought intotheknifedrum of the machine according to the invention quiteautomatically places itself with its fibres :parallel to the axis ofrotation, so that the direction of thefibreofthe flat shavings cut awaybythe planing knives onth'e periphery of the drum extends in the -planeof these shavings.

The novel features which are considered as characteristicfor theinvention are set forth in particular in the appended claims. Theinvention itself,,however, both as to its construction and its method ofoperation, together {with "additional objectsand advantages thereof,will be best understood from the following description of specificembodiments "when read in connection with the accom- .:panying drawings,in which:

- housing cover.

Figure 3 is asectionthroughapart of'the knife drum ron ,the-line III-IIIof Fig. 1. l

p The housing of the machine consists of the casing-1 and the cover 2.Cover 2 can be turned about the vertical hinge 6 and can be clamped tothe casing 1 by "screws "4. On the cover 2 is arranged the fillinghopper S through which'the wood to'be shaved is fed in, to be "guided bythe inner-cone 6, arranged on the housing cover-2, to the knife drum.

In the housing casing 1 is carried the hollow shaft 7 The knife drumconsists of a prefis attached by means of the bolts -9 which areparallel -to the it drum axis. Between the circular disc 8 and thepressing ring 10, which-are each provided with a ring groove'i17, areheld-the cylindrical ring Sectors 11, which carry, at the end leading inthe direction of rotation, planing knives 12 directed towards the innerside of the drum. Knives 12 are attached to sectors 11 by means ofpressing plates 13 and screws 14., At their other ends the sectors 11are provided with ventilating vanes 15 directed towards the outside ofthe drum, by means of which an air stream, directed towards the outside,is produced when the knife drum rotates. Thereby, the fiat shavings, cutaway by the planing knives 12 from the pieces of waste wood orientedparallel to the axis of rotation, are drawn into the outer peripheralpart 16 of the housing, from, where they are carried away for furtherprocessing or breaking up through the fall tubes 18.

In addition the knife drum is formed so that its ring of knives can beexchanged preferably as a whole, so

that the machine is only put out of operation for a short time when theplaning knives become blunt.

Inside the hollow shaft Z -of the knife dmm, and concentric therewith,is carried" the oppositely rotating shaft 9' which which carries theboss 20 with the'beating arms or plates 21, rotating 'inthe. interior ofthe knife drum,

fixed to the boss 20.

' a The waste wood fed in to the machine through the ing'the steps ofcentrifugally pressing against a plurality of knife blades rotatingabout a given axis and extending parallel to said axis a plurality ofpieces of wood each of which has a length'greater than its width andshorter than said knife blades and each of which has its fibersextending in direction of its length, so that said pieces 'of woodautomatically orient themselves in a position where their fibers extendsubstantially parallel to said axis; and cutting said pieces of woodinto shavings with said blades to provide shavings having fibersextending substantially parallel to the faces of said shavings.

2. A process for making flat wood shavings compris- I ing the steps ofcentrifugally pressing against a plurality of knife blades rotatingabout a given axis and extend ing parallel to said axis a plurality ofpieces of wood each of which has a length greater than its width andshorter than said knife blades and each of which has its fibersextending in direction of its length, so that said pieces of woodautomatically orient themselves in a position Where their fibers extendsubstantially parallel to said axis; cutting said pieces of wood intoshavings with said blades to provide shavings having fibers extendingsubstantially parallel to the faces of said shavings; and sucking thethus formed shavings radially outwardly beyond said blades.

3, A process for making flat wood shavings comprising the steps ofcentrifugally pressing against a plurality of knife blades rotatingabout a given axis and extending parallel to said axis a plurality ofpieces of Wood each of which has a length greater than its width andshorter than said knife blades and each of which has its fibersextending in direction of the length, so that said pieces of woodautomatically orient themselves in a position where their fibers extendsubstantially parallel to said axis; and positively moving said piecesof wood with respect to said blades in a direction opposite to thedirection of movement of said blades to cut said pieces of wood intoshavings having fibers extending substantially parallel to the faces ofsaid shavings.

4. A process for making flat wood shavings comprising the steps ofcentrifugally pressing against a plurality of knife blades rotatingabout a given axis and extending parallel to said axis a plurality ofpieces of wood each of which has a length greater than its width andshorter than said knife blades and each of which has its fibersextending in direction of its length, so that said pieces of woodautomatically orient themselves in a position where their fibers extendsubstantially parallel to said axis; positively moving said pieces ofwood with respect to said blades in a direction opposite to thedirection of movement of said blades to cut said pieces of wood intoshavings having fibers extending substantially parallel to the faces ofsaid shavings; and sucking the thus formed shavings radially outwardlybeyond said blades.

5. A machine for cutting wood or the like into shavings, comprising, incombination, a plurality of-knife blades; carrying means carrying saidknife blades in a position where the cutting edges thereof respectivelyform elements of a cylinder, said carrying means being formed with freespaces forming radial openings through said carrying means respectivelycommunicating with said knife blades; means supporting said carryingmeans for turning movement about the axis of said cylinder; a pluralityof plates respectively located substantially in planes which include theaxis of said cylinder, extending from said axis toward said blades, andconnected to each other other adjacent said axis so that the spacesbetween said plates are completely free except for the connectionbetween said'plates adjacent said axis; means supporting said plates forturning movement about said axis; means for feeding material to be cutto the spaces between said plates, said knife blades facing inwardlytoward said plates so as to receive material moving outwardly along saidplates and to out said material into shavings; and vane means carried bysaid carrying means for rotation therewith for creating a suction forcedirected outwardly through said radial openings of said carrying meansaway from said axis during rotation of said carrying means so as to sucksaid shavings cut by said blades through said opening outwardly awayfrom said blades.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES The Prall Mill, Colliery Engineering, October 1952, pp. 433,434, volume 29, issue 344.

